public class Example4_20{
  public static void main(String args[]){
  char a[]={'a','b','c','D','E','F'};
  for(int i=0;i<a.length;i++){
  if(Character.isLowerCase(a[i]))
     a[i]=Character.toUpperCase(a[i]);
  else if (Character.isUpperCase(a[i]))
    a[i]=Character.toLowerCase(a[i]);
  }
  for(int i=0;i<a.length;i++)
    System.out.print(" "+a[i]);
    }
}
